I Am Pregnant And Between 4 To 6 Weeks, Undetermined

I am pregnant and between 4 to 6 weeks, undetermined due to my irregular period cycles. I have been having a brownish-pink to purple type of discharge, with very light cramping (mostly feels like sore muscles).This is my first pregnancy and I am 32. I have always wanted to have a baby and it just never happened, so the thought of something bring wrong is scary. I went to the hospital and they said my beta hormone count was at 5,453.27 and that my uterus looked fine, they did an ultrasound and my gestational sac was there but they couldn't spot the yolk or a fetal pole. I am on bed rest for 48 hrs and have a follow-up for tomorrow to recheck my beta count and make sure it's still rising, I'm doing my best not to stress and relax but can't help wanting a second reassuring that things are okay. Is it normal to have that discharge? Is it common not to be able to spot the yolk this early. They did the vaginal ultrasound and couldn't see it. I just need to know if these things are common......